<template>
<div class="filterbar">
      <div class="filterbar-title">
        <ul class="title-ul">
            <!-- 遮罩层的每条数据 -->
          <li
            :class="{'title-li':true, 'current': item.isShow}"
            v-for="(item, index) in barMenus"
            :key="index"
          >
            <span @click="handerClickMenu(item)">
              {{item.name}}
              <van-icon :name="item.isShow ? 'arrow-up' :'arrow-down'" />
            </span>
            
            <div class="filterbar-content" v-on:click.stop v-if="item.isShow">
              <ul class="content-ul">
                <li
                  v-for="(child, number) in item.data"
                  :key="number"
                  
                  :class="{'current': child.selected}"
                  @click="handerClickContent(item, child)"
                >
                  {{child.name}}
                  <van-icon v-if="child.selected" name="success" />
                </li>
              </ul>
              
              <div class="button-div" v-if="item.multiple">
                <van-button plain type="default" @click="handerClear(item)">清空</van-button>
                <van-button type="info" @click="search">确定</van-button>
              </div>
            </div>
          </li>
        </ul>
      </div>
      <!-- 点击确定进行筛选 -->
      <div class="bg-filterbar" v-if="isBgFilterbarShow" @click="handerClickMenu"></div>
    </div>
</template>
<script>
export default {
  data() {
    return {
      barMenus: [
        {
          name: "菜系",
          value: 1,
          isShow: false,
          multiple: true,
          data: [
            { name: "川菜", value: 1, selected: false },
            { name: "粤菜", value: 2, selected: false },
            { name: "湘菜", value: 3, selected: false },
            { name: "苏菜", value: 4, selected: false },
            { name: "闽菜", value: 5, selected: false },
            { name: "徽菜", value: 6, selected: false },
            { name: "浙菜", value: 7, selected: false },
            { name: "鲁菜", value: 8, selected: false }
          ]
        },
        {
          name: "口味",
          value: 2,
          isShow: false,
          multiple: true,
          data: [
            { name: "清淡", value: 1, selected: false },
            { name: "麻辣", value: 2, selected: false },
            { name: "养生", value: 3, selected: false }
          ]
        },
        {
          name: "适合人群",
          value: 3,
          isShow: false,
          multiple: true,
          data: [
            { name: "老人", value: 1, selected: false },
            { name: "婴儿", value: 2, selected: false },
            { name: "小孩", value: 2, selected: false },
            { name: "病人", value: 2, selected: false }
          ]
        },
        {
          name: "排序",
          value: 4,
          isShow: false,
          multiple: false,
          data: [
            { name: "做过最多", value: 1, selected: false },
            { name: "点赞最多", value: 2, selected: false }
          ]
        }
      ]
    };
  },

  computed: {
    isBgFilterbarShow: {
      get() {
        let isBgShow = false;
        this.barMenus.forEach(function(currentValue, index, arr) {
          if (currentValue.isShow) {
            isBgShow = true;
          }
        });
        return isBgShow;
      }
    }
  },

  methods: {
    search() {
      this.handerClose();
    },

    handerClose() {
      this.barMenus.forEach(function(currentValue, index, arr) {
        currentValue.isShow = false;
      });
    },

    handerClickMenu(item) {
      if (!item) {
        return;
      }

      this.barMenus.forEach(function(currentValue, index, arr) {
        if (currentValue.value == item.value) {
          currentValue.isShow = !currentValue.isShow;
        } else {
          currentValue.isShow = false;
        }
      });
    },

    handerClickContent(item, child) {
      if (!item.multiple) {
        this.handerClear(item);
        this.handerClose(item);
      }

      child.selected = !child.selected;
    },

    handerClear(item) {
      item.data.forEach(function(currentValue, index, arr) {
        currentValue.selected = false;
      });
    }
  }
};
</script>

<style lang="scss">
 .filterbar {
    position: fixed;
    z-index: 2;
    left: 0;
    top: 3.1em;
    width: 100%;
    background-color: #fff;
    height: 2em;

    .bg-filterbar {
      position: fixed;
      width: 100%;
      height: 100%;
      background-color: black;
      opacity: 0.2;
      z-index: 1;
      left: 0;
      top: 4.2em;
    }
    .filterbar-title {
      width: 100%;
      .title-ul {
        height: 1.4em;
        margin-bottom: 0.5em;
        border-bottom: 1px solid #eee;
      }
      ul .title-li {
        width: 24%;
        float: left;
        text-align: center;
        font-size: 0.9em;

        .filterbar-content {
          position: absolute;
          left: 0;
          width: 100%;
          padding: 0.5em;
          background-color: #fff;
          z-index: 2;
          top: 1.24em;
        }
        .content-ul li {
          text-align: left;
          color: #111;
          font-weight: 400;
          padding-left: 1.5em;
          padding-top: 0.7em;
        }
        .content-ul .current {
          color: #1989fa;
        }
      }
      ul .current {
        color: #1989fa;
        font-weight: 600;
      }
      ul:after {
        content: "";
        display: block;
        clear: both;
      }
      .content-ul .van-icon {
        float: right;
        margin-right: 2.5em;
      }
      ul .van-icon {
        vertical-align: middle;
      }
    }
    .button-div {
      margin-top: 1.5em;
      text-align: center;

      button {
        width: 48%;
        float: left;
      }
      .van-button {
        height: 3em;
        line-height: 3em;
        font-size: 1em;
        font-weight: 400;
      }
    }
  }
</style>